>Make it a candidate key and do some error trapping because you WILL get an error if you try to update a duplicate value, or trap it logically using a SEEK to look for the value before updating the table and make it any type of key you want.

Just to be clear: You may have to re-open the table with another alias and do the seek() on that. If you've got row bufferning, doing a seek will move the record pointer, try and update the table and if it is a duplicate key you'll get the error message anyways.

Or you can use IndexSeek(), I believe. In either case, if they Return True, you have to check the primary key or record number to make sure the key you found isn't the one you're trying to save.